In this Menu:
<ul>
-<li><b>Shape Type</b> radio button define the type of elements for the
+<li><b>Shape Type</b> radio button defines the type of elements for the
group (points, wires, faces, shells or solids).</li>
<li><b>Group Name</b> - here you can enter the name of the group, by
default, it is Group_n.</li>
<li>Then, using the "Select" button, select the <b>Main Shape</b> (a
-geometrical object on which the group will be created). You can select
-the elements of your group in two ways: </li>
+geometrical object on which the group will be created). </li>
+<li> <b>Select Sub-Shapes</b> button group lets you restrict the range
+of group elements you operate with.
+<ul><li>\b All button enables work with all sub-shapes of the Main
+Shape.</li>
+<li><b>In Place of Second Shape</b> restricts the range of accessible
+elements to those sub-shapes of the Main Shape that geometrically
+coincide with the <b>Second Shape</b>.</li>
+<li><b>Sub-Shapes of Second Shape</b> restricts the range of
+accessible elements to those sub-shapes of the Main Shape that
+are sub-shapes of <b>Second Shape</b>. This is useful because
+sometimes purely geometrical coincidence is not enough and it
+is necessary to work with shapes, which actually belong both
+to the main and the second shape.</li>
+</ul>
+<li> You can select the elements of your group in two ways:
<ul>
-<li>Clicking <b>Select Sub-Shapes</b> button you can select them
-manually in the 3D Viewer, and add to the group by clicking the \b Add
-button (keep down the Shift button on the keyboard to select several
-elements and add all them together). The indexes of the selected
-elements will be displayed in the list. To delete elements from the
-list, select them and click \b Remove button.</li>
+<li>You can select them manually in the 3D Viewer, and add to the
+group by clicking the \b Add button (keep down the Shift button on the
+keyboard to select several elements and add all them together). The
+indexes of the selected elements will be displayed in the list. To
+delete elements from the list, select them and click \b Remove
+button.</li>
<li>Clicking <b>Select All</b> button you can add all object's
elements of a certain type in the list of the elements of the
-group. To delete elements from the list, select them and click \b
-Remove button.</li>
-</ul>
-<li>Finally, confirm your selection by clicking \b OK (also closes the
-Menu) or \b Apply (leaves the Menu open for creation of other groups),
-or skip it by clicking \b Close button.</li>
-</ul>
+group. If the <b>Second Shape</b> is used, the elements are added
+according to <b>Select Sub Shapes</b> setting. To delete elements
+from the list, select them and click \b Remove button.
+</li></ul>
+</li>
+<li>Finally, confirm your selection by clicking <b>Apply and Close
+</b> (also closes the Menu) or \b Apply (leaves the Menu open for
+creation of other groups), or skip it by clicking \b Close button.
+</li></ul>
\n The Result of the operation will be a \b GEOM_Object.
